I recently was unable to boot into my home Linux Desktop, it got stuck at
fsck. I found that I was able to get in to a tty through a hotkey.
What's a TTY?
There's probably more to it, but to me its a full screen terminal with zero gui, not even your gui fonts. It does log into your default shell so if you have a comfy command line setup it will be here for you even though it looks much different without fonts and full colorspace.
Normally you have 6 TTY's running, the first is dedicated to your desktop manager, which is your login screen it might be something like gdm or lightdm.
- ctrl+alt+F1: login screen
- ctrl+alt+F2: Desktop
- ctrl+alt+F3: TTY 3
- ctrl+alt+F4: TTY 4
- ctrl+alt+F5: TTY 5
- ctrl+alt+F6: TTY 6
In my case the desktop manager neverstarted, so ctrl+alt+F1 brought me into a tty.
Well after getting back in and having some time to reflect, I think my Desktop manager was installed or just broken, possibly during a update I ran a few days prior.
I tried a bunch of things like switching to lightdm, and manually running startx.
Getting back in
The final commands that ended up getting me back in were installing and starting gdm3.
sudo apt install gdm3 sudo systemctl start gdm3